public class Demo {
    public static void main(String[] args) {
        int x = 0;
        int a = 3;
        int b = 6;
        System.out.println(x^a);
        System.out.println(a^b);
        String s1 = "a";
        String s2 = "b";
        System.out.println(s1.compareTo(s2));
    }
}
